There is strong interest in nanocomposites due to the opportunity to prepare compositions with improved properties over those of the starting polymers through controlling the size and dispersion of fillers therein. Silicate fillers (many of which are mined and require only minimal processing before use) are available that include within each particle a multitude of platelike layers. During most conventional polymer processing steps the individual plates do not separate but rather the aggregates of many platelike layers are dispersed as a single particle. Some authors have found ways to pretreat silaceous fillers (often using the monomeric form of the matrix polymer) to cause intercalation and exfoliation with specific polymers.
Nanocomposites from nylon in the prior art exhibited substantial improvement in mechanical , thermal and Theological properties. Nanocomposites from epoxies exhibited improved tensile modulus and strength. Suspension of a sheet silicate in solvents such as water, acetonitrile, dimethyl acetamide (DMAC) has resulted in intercalated hybrids of poly(ethylene oxide). Melt methods have lead to the intercalation of polystyrene and exfoliated nanocomposites of epoxy via melt interlayer polymerization. Interlayer polymerization has also produced intercalated polystyrene, intercalated poly(.epsilon.-caprolactone), and poly-6-amide by intercalation of .epsilon.-caprolactam. Other approaches such as sol-gel process and monomer/polymer grafting to clay layers have also resulted in polymer clay hybrids.
Using an oligomeric form of the matrix polymer as an additive, allows the additive to swell the clay. For example Okada et al. have reported using a polyolefin oligomer with polar telechelic hydroxyl groups to prepare a polypropylene clay hybrid.